Since hypertension and insulin resistance are associated with disturbed lipoprotein metabolism, and converting enzyme inhibition improves the glucose aspects of insulin resistance, the investigators hypothesize that the renin-angiotensin system contributes to insulin resistance in lean hypertensives. They will study 20 subjects (10 treated with diuretic, 10 with ramipril, an ACE inhibitor) over 10 wks using stable isotopes to evaluate the effect of therapy on glucose and lipid metabolism using the euglycemic clamp.